Thermoplastic molding systems generally employ a mold having a mold cavity therein, into which molten thermoplastic material is injected under pressure. The mold generally includes two or more mold pieces that define the mold cavity between the mold pieces when the mold pieces are adjoined to one another. The molding system generally includes two platens that support the mold pieces, respectively. One or both of the mold platens is movable, such that the mold may be closed to perform a molding cycle, and subsequently opened to allow removal of the molded part from the mold. As the molten thermoplastic material is injected under pressure, the thermoplastic material exerts pressure against the mold pieces that generates separating forces between the mold pieces. Therefore, the platens must apply counteracting closing force to the mold pieces to maintain the mold closed during the molding cycle. The closing force that the platens must apply to the mold increases with increasing size of the article being molded in the mold cavity. Thus, molding systems for molding relatively large articles of manufacture can be extremely large, and can require high hydraulic pressure and electric power for operation.